Double tube core barrel for core drilling



Dec. 5, 1950 J. L. HAVLICK Filed NOV. 28. 1947 F /'g. 2. F ig. /7

2 Sheets-Sheet 1 Fig.3.

4 Inventor A J Jesse L. Ha v/ic/r Mp/W 1950 J. L. HAVLICK 2,532,716

DOUBLE TUBE CORE BARREL FOR CORE DRILLING Filed NOV. 28. 1947 2She'hS-Shmit 2 Inventor Jesse L. #0 v/ick By M9:

Patented Dec. 5, 1950 DOUBLE TUBE com: BARREL FOR CORE DRILLING fortyper cent Wash.

Jesse L. Havlick, Spokane, Wash., assignor of to Gerben Meidema,Spokane,

Application November '28, 1947, Serial No. 788,427

' Claims (01. 255-72) M invention relates to improvements in doubletubecore barrels for use in obtaining sample coresincore drillingoperations.

E :The primary object of my invention is to achieve, especially in coredrilling in soft formations, better core delivery to the collar of thehole than has heretofore been possible with core barrels of commerce. V

Another object is to provide improved means for. retaining the core inthe bit and picking up the core closer to the bottom of the hole thanhas heretofore been possible.

Still another object is to seal .olf from the core, duringthe drillingoperation, water circulating through the barrel to the bottom of thehole for drilling purposes;...

-..:Still.another objectv is to provide for discharging such water atthe leading end of the bit to facilitate drilling;

Still another object to. provide, when the drilling period is ended,either by the barrel be issimple in construction, will not get out oforder,

and .is comparatively inexpensive to manufacture and use.

. Other and subordinate objects, also, within the purview of. myinvention, together with the precise nature of my improvements, will bereadily understood when the succeeding description and claims arereadwith reference to the drawings accompanying and forming part of thisspecification.

. In said drawings: Figure 1 is a view in side elevation, partly brokenaway, of my improved double tube core barrel in a preferred embodimentthereof; "Figure 2 is a view in longitudinal section, partly insideelevation, taken on the line 2-2 of Figure 1; 7

i Figure 3 is a fragmentary view in vertical section taken on the line3-3 of Figure 2 and drawn toa larger scale; Q

Figure 4* Ba similar view taken on the line 4-4 of Figure 2;

""Figure 5 is a view in end elevation of the head section drawn to alarger scale;

IL'Figure 6 is a view in transverse section taken on the line 6-6 ofFigure '3; 4 v k Figure 7 is a similar view taken. on line 'l-'l ofFigure 4;

Figure 8 is another similar view taken 0 lined-J of Figu e 4;

. 2 Figure 9 is a view in side elevation of the core lifter drawn to alarger scale; and

Figure 10 is a view in plan of the core lifter.

Referring to the drawings by numerals, my im proved core barrel, asshown, comprises a cylindrical head section l with a lower reduced,externally threaded end 2. The head section I is formed. with the usualinternally threaded upper sleeve portion 3 for connection to the usualhol-- low rotating drill stem, not shown. A lower end, axial bore 4 isprovided in said head section I and an axial reduced water return boreleading from said bore 3 to the interior of the sleeve portion 3.Longitudinal water discharge ports 6 extend from the sleeve portion 3 tothe lower end of said head section I and are grouped around the bores 4,5 in downwardly flaring relation.

An outer core barrel section I is threaded at its upper end onto thelower end of said head section I for rotation therewith, and with atubular shell section 8 threaded onto the lower end thereof of slightlysmaller internal diameter than said core barrel section I and providedwith longitudinal water passage grooves 9 therein.

A tubular diamond point core bit Hi, shown without the diamond points assulficient for the present purposes, is threaded onto the lower end ofthe shell section 8. The drill bit H1 is provided with the usualdownwardly tapered, intermediate bore portion ll which, in thisinstance, is spaced below the lower end of the shell section 8.Longitudinal water discharge ports l2 are provided in the drill bit, Illextendin from the upper end of said bore portion ll tothe bottom, orleading face of said drill bit.

An inner, relatively smaller diameter core bar-' rel section I3 isyieldingly suspended, rotatably, in the outer core barrel section I fromthe head section. and in spaced relation to said outer core barrelsection I to permit water to pass between said barrel sections, thesuspension means comprising the following.

A guide bolt I4 with an upper end threaded into the bore 4 dependsaxially from the head section I with a lower end head it thereon and anaxial water return bore [6 extending therethrough into communicationwith the water return bore 5.

An end thrust ball bearing assembly l'lsur rounding said bolt l4 restson the head 15 and supports thereon a sleeve I8 surrounding said bolt Mwith a liner bushing l9, said sleeve l8 having the upper end of theinner core barrel section 13 suitably fixed thereto flush therewith.

A second ball bearing assembly Zllsurroundingsaid bolt 14 rests on asealing washer 2! on top of the sleeve l8 and supports a cup-like sleeve22 surrounding said bolt M with a sealing washerv 23 between the bottomof said sleeve and said assembly 20.

A coiled expansion spring 24 surrounds said bolt I4 and is interposedbetween the bottom of said sleeve 22' and a flanged collar 25 on thebolt I4 clamped against the lower end of the head section I by ashoulder 26 on said bolt I4. The purpose of the collar 25 will presentlyappear.

As will be apparent, the sleeve I8 with its liner I9, and the ballbearing assembly 20 and sleeve 22 are slidable upwardly on the guidebolt I l in opposition to the tension exerted by the coil spring 24 topermit yielding upward movement of the inner core barrel section I3 inthe outer core barrel section 1, and said sleeves I3, 22, together withthe washers 2|, 23 and said assembly 29, are spaced from the outer corebarrel section 1 for the same purpose as the inner core barrel s6;- tionI3. Due to the described arrangement, the outer and inner core barrelsections 1, I3 are varranged for relative advance and retractionendwise. As best shown in Figure 4, in the normal downward, or advance,limit of movement of the inner core barrel section I3, as determined bythe head I of the guide bolt I4, in a manner which will be clear, thelower end of the inner core barrel section I3 is disposed in the bit It!below the lower end of the shell section 8 but above the tapered boreportion I I in said bit.

A core lifter 21 is attached to the lower end of the inner core barrelsection IS, in the downward limit of movement of said core barrelsection, in

the outer core barrel section 1, to extend downwardly into the taperedbore II part way. The core lifter 21 has the form of a tubular,longitudinally split body 28 of the same internal'diameter as that ofsaid inner core barrel I3, when ate tached, said body being formed ofresilient mate-. rial whereby the same tends to contractcircumferentially into reduced size diametrically. Longitudinal,laterally spaced ribs 29 on said body 21, of flat form, extend above theupper end thereof to form gripping fingers 39 for clamping engagementwith the periphery of the lower end of said inner core section IS in thespace between the lower end of said shell section 8 and said boreportion II. Shoulders 3| on the fingers 3B fiush with the upper edge ofthe body 28 seat the lower end of the inner core barrel section I3 withits inner circumferential wall flush with the corresponding wall of saidbody 28. The ribs 29 taper downwardly from the fingers 30 to fit saidbore portion I I and to a lower end feather edge 32 on said body 28fitting in said bore portion II so as to obviate forming a shouldertherein.

As will be understood, the described core lifter 21 when clamped to thelower end of the inner core barrel section I3, as described, is held bysaid barrel section in an expanded position. I n this connection, theedges 33 of the split in the body 28are beveled to overlap, as shown inFigure 10, in the expanded condition of the core lifter 2 I and so as toobviate an internal shoulder in said body 23 when said lifter is eitherexpanded or contracted. 7 An annular, flat, check valve member 34is-slidably mounted on the collar 25 for engagement with the upper endof the sleeve 22 to be slid thereby upwardly against the lower end ofthe head section I in covering relation to the lower ends of the waterdischarge ports 6, to thereby close said ports. The valve member 34,when re leased, slides downwardly on said collar 25, under the influenceof gravity, into port-opening position.

Suitable hard metal ware sleeves 35, 36 are 4 provided on the headsection I and the outer barrel section 1 where desirable.

Referring now to the operatiQll 0f the described invention ,the core,not shown, passes upwardly through the bit I0 into the inner barrelsection I3 freely, without any spring pressure being exerted against thesame by the core lifter 21, the body 28 of said lifter acting as a guidefor the core and as a guard to protect the lower end of the inner corebarrel section against wear. The core lifter 21, when expanded,substantially seals off the core, during the drilling period, from thewater circulating through the barrel. In my improved core barrel, thewater passes downwardly from the head section I through the discharge prt 6, the pace bet e the out r and nne core barrel sections 1, I3, thegrooves 9 in the. shell section 8, and the discharge ports I2 in the bitI0 and discharges at the iace or leading end of said bit to returnthrough the bit ,I 0, core lifter 21, inner core barrel section I3 andthe return port I6 to the head section I, which is to say the. uppersleeve portion 3 thereof.

When the drilling period is ended, either by the inner core barrelsection I3 being filled with core, or by the core blocking or wedging insaid sec-: tion, the inner core barrel section I3. will remainstationary while the outer core barrel section 1 continues to rotatewith the bit I0 and to advance relative to said inner core barrelsection I3. This advance of the outer core barrel section .1 causes thelower end of the shellsection 8 to engage the fingers 3t and therebypush the core lifter 21 off the lower end of the inner core barrelsection [3, at which point said core lifter ,21 contracts about the coreto yieldingly grip the same. Such ad- Vance of the outer core barrelsection 1 also causes the check valve member 34 to be engaged with theupper end of the sleeve .22 and thereby moved upwardly to close thedischarge ports vIi and block the circulation of water through thebarrel. This will cause a drill operator at the surface to notice achange in pressure on the pressure gauge, not shown, of the usual watercirculating pump, not shown, at the surface, whereby the drillingoperator will be advised that the barrel should be lifted out of thehole, not shown, being drilled in. As soon as the drill operator startsto lift the barrel from the bottom of the hole, the core lifter 21 isforced down in the bit III by ad Vance of the inner core barrel sectionI3 relative to the outer core barrel section 1, such advance of theinner core barrel sections I3 being caused by the coil spring 24previously compressed by the described advance of the outer core barrelsection 1 relative to the inner core barrel section. This forcing of thecore lifter 21 down in the bit Ii] results in the tapered bore portionII incoaction with the ribs 29 forcing said core lifter into furthercontracted position about the core, thus insuring retaining of the corein the bit and picking up of the core close to the bottom of the hole.

The foregoing will, it is believed, suffice to impart aclearunderstanding of my invention, without further explanation. V

Manifestly,ethe invention, as described, is susceptible of modificationwithout departing rm the inventive concept, and right is herein reservedto such modifications as fall within the scope of the appended claims.

Having described the invention, what is claimed as new is:

1. A core barrel comprising a head section- 'for thereby, an outer corebarrel section fixed to and depending from said head section forrotation therewith, a tubular drill bit depending from the lower end or"the outer core barrel section and fixed thereto for drilling a core, aninner core barrel section for receiving said core, means to mount theinner core barrel section on said head section to provide for relativeendwise advance and retraction of said outer and inner core barrelsections comprising a bolt depending axially from head section, and asleeve fixed to the upper end of the inner core barrel section andslidable and rotatable on said bolt, and an annular core lifter slidablyfitted on the lower end of the inner core barrel section and in said bitfor sliding oil end and being engageable by the lower end of the outercore barrel section to be thrust downwardly oil the inner core barrelsection upon advance of said outer section relative to said innersection, said lifter being resilient for contraction in suiiicientdegree to grip the core in said bit when said lifter is thrust off theinner core barrel section.

2. A core barrel comprising a head section for attachment to a hollowdrill stem to be rotated thereby, an outer core barrel section fixed toand depending from said head section for rotation therewith, a tubulardrill bit depending from the lower end of the outer core barrel sectionand fixed thereto for drilling a core, an inner core barrel section forreceiving said core, means to mount the inner core barrel section onsaid head section to providefor relative endwise advance and retractionof said outer and inner core barrel sections comprising a bolt dependingaxially from said head section, and a sleeve fixed to the upper end ofthe inner core barrel section and slidable and rotatable on said bolt,an annular core lifter slidably fitted on the lower end of the innercore barrel section and in said bit for sliding off said end and beingengageable by the lower end of the outer core barrel section to bethrust downwardly off the inner core barrel section upon advance of saidouter section relative to said inner section, said lifter beingresilient for contraction in sufiicient degree to grip the core in saidbit when said lifter is thrust off the inner core barrel section, andcamming devices on said lifter and bit coacting during downward thrustof said lifter to further contract the same and tighten the grip thereofon said core.

3. A core barrel comprising a head section for attachment to a hollowdrill stem to be rotated thereby. an outer core barrel section fixedthereto and depending from said head section for rotation therewith, atubular drill bit depending from the lower end of the outer core barrelsection and fixed thereto for drilling a core, an inner core barrelsection for receiving the core, means to mount the inner core barrelsection on said head section to provide for relative endwise advance andretraction of said outer and inner core barrel sections comprising abolt depending axially from said head section, and a sleeve fixed to theupper end of the inner core barrel section and slidable and rotatable onsaid barrel, said head section being ported and said inner and outercore barrel sections being spaced apart for passing water to said bit.and valve means operated by advance of the outer core barrel sectionrelative to the inner core barrel section to close said ports and blockpassage of water to said bit.

4. A core barrel comprising a head section for attachment to a hollowdrill stem to be rotated thereby, an outer core barrel section fixed toand depending from said head section for rotation therewith, a tubulardrill bit depending from the lower end of the outer core barrel sectionfor receiving said core, means to mount the inner core barrel section onsaid head section to provide for relative endwise advance and retractionof said outer and inner core barrel sections comprising a bolt dependingaxially from said head section, and a sleeve fixed to the upper end ofthe inner core barrel section and. slidable and rotatable on said bolt,an annular core lifter slidably fitted on the lower end of the innercore barrel section and in said bit for sliding ofi said end and beingengageable by the lower end of the outer core barrel section to bethrust downwardly oif the inner core barrel section upon advance of saidouter section relative to said inner section, said lifter beingresilient for contraction in sufficient degree to grip the core in saidbit when said lifter is thrust oiT the inner core barrel section, andcamming devices on said lifter and bit coacting during downward thrustof said lifter to further contract the same and tighten the grip thereofon said core comprising downwardly converging ribs on said lifter, and adownwardly tapered bore portion in said bit.

5. A core barrel comprising a head section for attachment to a hollowdrill stem to be rotated thereby, an outer core barrel section fixedthereto and depending from said head section for rotation therewith, atubular drill bit depending from the lower end of the outer core barrelsection and fixed thereto for drilling a core, an inner core barrelsection for receiving the core, means to mount the inner core barrelsection on said head section to provide for relative endwise advance andretraction of said outer and inner core barrel sections comprising abolt depending axially from said head section, and a sleeve fixed to theup er end of the inner core barrel section and slidable and rotatable onsaid barrel said head section being ported and said inner and outer corebarrel sections being spaced apart for passing water to said bit. andvalve means opera ed by advance of the outer core barrel sectionrelative to the inner core barrel section to close said ports and blockpassage of water to said hit comprising an annular valve membercircumscribing said bolt and mova le relative thereto to clo e saidports, and a member on said bolt for moving the valve member when saidouter core barrel is advanced relative to said inner core barrel.

JESSE L. I-IAVLICK.

REFERENCES CITED The fol owin references are of record in the file ofthis patent:

UNILi ED STATES PATENTS Num er Name Date Re.1 45 Baker Apr. 14, 19311,611,504 Baker Dec. 21, 1926 1.253 581 Schmissrauter et al. Apr. 12,1932' 1.903.232 Giesey Mar. 28, 1933 1994.848 Baker et al Mar. 19, 19352.001.764 Bradley May 21, 1935 2,040.899 Whinnen May 19, 1936 2.260 6'78Muhlbach Oct. 28, 1941 2,422,955 Duffield June 2 1, 1947 FOREIGN PATENTSNumber Country Date 5.300 Great Britain 1914 608,248 Germany Jan. 18,1935

